Flying boat



E. zlND FLYING B April 1, 1930.

Filed June 1938 A Patented Apr. 1,1930

' uui'rso STATES PATENT OFFICE mar or nnssnu, enmnx, nssmnon 'ro nuooJUNKEBS, or nnseau,

. a em ammo Boar Application med June't), 192e, serial No. 284,059, andin Germany February I' l, 1928.

.My invention refers to flying machines and more es ecially to that typewhich is called flying oat because thefu selage resembles the hull of aboat and is adapted to rest on andbe partly immersed, in the water. Myinvention has particularly reference to flying boats having two parallelfuselages in the form of boats, hulls, which are spaced symmetricallyand in parallel to the middle axis of the craft.

Flying boats of the twin-hull type offer the advantage, as compared withsin le-hull ma-- chines, of presenting greater sta ility when floatingonthe water. On the other hand this type of flying boats involves adisadvantage, which becomes apparent more particularly in twin-hullmachines of the monoplane type with a self-supporting wing, in which thewin forms the only connection between the two ulls. This disadvantageconsists therein that the middle portion of the wing intermediate thetwo hulls is subjected to severe bending and torsional" stresses byshocks, for inv stance the impact of waves acting on a hull from theside or when the buoyancy is not evenly distributed on the two hulls,for instance in the case where the craft moves forward in obliquedirection to high waves.

' versal The resent invention is concerned with means or increasing theresistivity of this middle portion of the wing structure intermediatethe two hulls. To this end I provide braces or struts secured to thebottom parts of the adjoining side walls of the two hulls, these bracesor struts being either connected with each other in fixed pointsunderneath the girder connecting the two hulls, or in points formingpart of the middle wing-portion, so that this bracing structure assiststhe girder in taking up the stresses acting thereon.

I may arrange such bracing connections in a'singletransversal plane, butI prefer providing such structures in at least two transpllanes at aconsiderable distance from each 0t er, as in this manner I obtain a moreeflicient resistivity against torsional stresses. Preferably the ends ofthe struts fixed to the boats hulls are secured to a middle hullarranged in the middle 'axis of the craft and projecting downwards fromthe wing without acting as a floating body. I may however also provideauxiliarystructures below the bottom of the mlddle wing portion, theconnecting securing the hulls.

In the drawings aflixed to this specificatio and formlng part thereoftwo flyng boats ein bodying my invention are illustrateddiagrammatically by way of example.

In the drawings Fig. 1 is a vertical longitudinal section on the line IIin Fig. 2, while Fig. 2 is a front view and 3 is a plan view ofone-modification.

t F 1g. 4; is a front view of another modifica- Referring to thedrawings and-more particularly to Figs. 13, 1 and 2 are the two hullsserving as floating bodies and 3 is a mid, dle hull arranged betweenthem without how/- ever extending down to the water surfac. These threehulls are interconnected by a girder constituted by the middle portionjdf the self-supporting wing 4. In order to tblri-e this wing portion ofthe bending and t'orsional stresses arising more particularly n a heavysea, struts 11, 12 extend from the ttorn parts of the hulls 1, 2 to thebottom, art of the middle hull 3. As shown in Figs. 1 and 3, two suchbracing structures are provided between the two hulls 1 and 2.

In the modification illustarted in Fig.4, which is not provided with amiddle hull projecting below the bottom of the wing, auxiliary bracingstructures are provided below the wing bottom, consisting of struts 13and horizontal braces 14:. The struts 1,1 and 12 fixed to the boatshulls 1, 2 are secured to the connecting points 15, 16 of the auxiliarybracing structure.

My invention may be applied with equal advantage also tocompound-machines of the amphibium type which form a combination of landand seaplane and in which besides the floating bodies a separate landingcarriage is provided. This modification is indicated in dotted lines inFigs. 1. and 2, which show a wheel 21, 22 arranged on each hull directlyin front of the step 23, an auxiliary pike 24 being provided at the endof each hull. These points of such auxiliary structure serving for theinner ends of the struts fixed to wheels'and auxiliary pikes maybearranged to be folded up in a well known manner in order that thepropulsion of the boats in the water be hindered as little possible.

I wish it to be understood that I do not desire to be limited to theexact details of construction shown and described for obviousmodifications will occur to a person skilled in the art.

I claim 1. A flying boat of the monoplane twinhull type, comprisin awing forming a continuous beam, two oating hulls adapted to carry theentire weight of the craft, said hulls being rigidly fixed to andextending below the bottom of said wing in spaced relation andsubstantially parallel to the longitudinal middle axis of the craft, andmeans spaced from said wing for bracing the adjoining side walls of saidhulls against each other and for reintorcing the ortion of said wingintermedi-v ate said hu s.

2. A flying boat of the monoplane twinhull type, comprising a wingforming a continuous beam, two floating hulls adapted to carry theentire weight of the craft, said hulls bein rigidly fixed to andextending below the ottom of said wing in spaced relation andsubstantially parallel to the longitudinal middle axis of the craft, andmeans spaced from said win for bracing the adjoining side walls of saidhulls against each other and against the middle portion of said wing andfor reinforcing the portion of said wing intermediate said hulls.

3. A flying boat of the monoplane twinhull type, comprising a winforming a continuous beam,'two floating ulls adapted to carry the entireweight of the craft said hulls being rigidly fixed to and extendingbelow the bottom of said win in spaced relation and substantiallyparallel to the longitudinal middle axis of the craft, and struts spacedfrom said wing for bracing the ad'oining side walls of said hullsagainst each 0t er and for reinforcin the portion of said wingintermediate said ulls.

4. Aflying boat of the monoplane twinhull type, comprisin a wing formingacontinuous beam, two oating hulls ada ted to carry the entire weight ofthe craft, sald hulls being rigidly fixed to and extending below thebottom of said win in spaced re ationand substantially para el to thelongitudinal middle axis of the craft, and struts spaced from said wingfo bracing the adjoining side walls of said hurls against each other andagainst the middle portion of said wing and for reinforcing the portionof said wing intermediate said hulls.

5. A flying boat of the monoplane twinhull type, comprising a wingforming a continuous beam, two floating hulls adapted to carry .theentire weight of the craft, said hulls being rigidly fixed to andextending below the bottom of said wing in spaced relation andsubstantially parallel to the longitudinal middle axis of the craft, andmeans spaced fronrsaid wing and extending in two longitudinally spacedplanes for bracing the adoining side Walls of said hulls against eachother and for reinforcing the portion of said wing intermediate saidhulls.

6. A flying boat of the monoplane twinhull type, comprising a wingforming a continuous beam, two floating hulls adapted to carry theentire weight of the craft, said hulls being rigidly fixed to andextending below the bottom of said wing in spaced relation andsubstantially parallel to the longitudinal midd Is axis of the craft,and struts spaced from said wing and extending in two longitudinallyspaced planes for bracing the adjoining side walls of said hulls againsteach other and against the middle portion of said wing and forreinforcing the portion of said wing intermediate said hulls.

7. A flying boat of the monoplane twinhull type, comprising a wingforming a continuous beam, two floating hulls adapted to carry theentire weight of the craft, said hulls being rigidly fixed to andextending below the bottom of said wing in spaced relation andsubstantially parallel to the longitudinal middle axis of the craft, andmeans for bracing the adjoining side Walls of said floating hullsagainst each other and agaiust the middle portion of said wing, saidmeans including a hull extending below the bottom of said wingintermediate said floating hulls.

In testimony whereof I affix my signature.

ERNST ZINDEL.

